The rotational profile of the Sun is considered to be one of the key inputs in a solar dynamo model. Hence, precise and long-term measurements of this quantity is important for our understanding of solar magnetism and its variability. In this study, we use the newly digitised, white-light sunspot data (1923 – 2011) from Kodaikanal Solar Observatory (KoSO) to derive the solar rotation profile. An automated correlation-based sunspot tracking algorithm is implemented to measure the rotation parameters, \(A\), the equatorial rotation rate, and \(B\), the latitudinal gradient. Our measurements of \(A=14.381\pm 0.004\) deg/day and \(B=-2.72\pm 0.04\) deg/day compare well with previous studies. In our analysis, we find that the bigger sunspots (with area > 400 μHem) rotate slower than the smaller ones. At the same time, we do not find any variation in the rotation rates between activity extremes, i.e. solar maxima and minima. Lastly, we employ our tracking algorithm on the Michelson Doppler Imager (MDI) data and compare the MDI results with our KoSO values.

太阳的旋转轮廓被认为是太阳发电机模型的关键输入之一。因此，对该量的精确和长期测量对于我们了解太阳磁及其可变性很重要。在这项研究中，我们使用来自Kodaikanal太阳观测站（KoSO）的新数字化白光黑子数据（1923 – 2011）得出太阳旋转剖面。实现了基于自动相关性的黑子跟踪算法，以测量旋转参数\（A \），赤道旋转速率和\（B \），纬度梯度。我们对\（A = 14.381 \ pm 0.004 \） 度/天和\（B = -2.72 \ pm 0.04 \）的测量 deg / day与以前的研究比较好。在我们的分析中，我们发现较大的黑子（面积大于400μHem）旋转得比较小的黑子慢。同时，我们没有发现极端活动（即太阳最大值和最小值）之间的旋转速率有任何变化。最后，我们对Michelson Doppler Imager（MDI）数据采用跟踪算法，并将MDI结果与我们的KoSO值进行比较。